Cattle farm dust alters cytokine levels in human airway construct model.

Epidemiological studies have revealed some alterations in systemic immunity that associate with farm exposure and the risk of respiratory diseases, but in vitro studies focusing on immunological responses in the airways are scarce. Our aim was to assess how cowshed dust affects the integrity and inflammation of human airway tissue in vitro. Cowshed dust samples were collected from four different dairy farms. Lung tissue constructs were exposed to dust samples in air-liquid interface. Transepithelial resistance of the tissue, secreted proteins, and a panel of pro-inflammatory cytokines, growth factors, and chemokines were analysed. Cowshed dust stimulation was associated mainly with increased production of IL-13, IL-15, IP-10 and IFN-γ. Some differences between farms were seen. Only one farm dust sample induced a significant change in transepithelial resistance, whereas dust from two of the farms induced the secretion of proteins. The exposure to cowshed dust affected protein and cytokine secretion, but the response profiles were not uniform between farms. The effect on tight junction dynamics was less pronounced, suggesting the relevance of soluble factors in induced responses in the airways. Our results indicate that in addition to farm type, the contribution of cowshed characteristics to dust composition and its immunomodulatory properties should be taken into account.

Toxicological transcriptome of human airway constructs after exposure to indoor air particulate matter: In search of relevant pathways of moisture damage-associated health effects.

BACKGROUND: Multiple health effects are associated with moisture damage in buildings. Studies explaining these associations and cell-level mechanisms behind the observed health effects are urgently called for. OBJECTIVES: We focused on characterizing gene expression in human airway epithelium after exposure to indoor air particulate matter (PM) sampled from houses with and without moisture damage, alongside determination of general toxicological markers. METHODS: We performed detailed technical building inspections in 25 residential houses and categorized them based on the detection of moisture damages and the probability of occupant exposure. PM sampling was complemented by microbiological and volatile organic compound assessment. We exposed human airway constructs to three dilutions (1:16, 1:8, 1:4) of collected PM from moisture-damaged (index) and non-moisture-damaged (reference) houses and imaged selected constructs with electron microscopy. We analyzed general toxicological markers and the RNA of exposed constructs was sequenced targeting genes associated with toxicological pathways. We did groupwise comparisons between index and reference houses and pairwise comparisons in matched index/reference houses. RESULTS: In groupwise comparison, gene Cytochrome P450 Family 1 Subfamily A Member 1 (CYP1A1) was statistically significantly over-expressed in index houses at all dilutions of collected PM and Nuclear Factor Kappa B Subunit 1 (NFKB1) at dilution 1:4 of collected PM. In pairwise index/reference house comparison, several genes related to multiple toxicological pathways were activated, largest expression differences seen for CYP1A1. However, none of the genes was consistently expressed in all the matched pairs, and general toxicological markers did not differentiate index and reference houses. DISCUSSION: The exposure to PM from index houses activated toxicology -related genes in airway constructs. Differential expression was not consistent among all the index/reference pairs, possibly due to compositional differences of bioactive particles. Our study highlights CYP1A1 and NFKB1 as potential targets in moisture damage -associated cellular responses.

Visualising household air pollution: Colorimetric sensor arrays for monitoring volatile organic compounds indoors.

Indoor air quality monitoring as it relates to the domestic setting is an integral part of human exposure monitoring and health risk assessment. Hence there is a great need for easy to use, fast and economical indoor air quality sensors to monitor the volatile organic compound composition of the air which is known to be significantly perturbed by the various source emissions from activities in the home. To meet this need, paper-based colorimetric sensor arrays were deployed as volatile organic compound detectors in a field study aiming to understand which activities elicit responses from these sensor arrays in household settings. The sensor array itself is composed of pH indicators and aniline dyes that enable molecular recognition of carboxylic acids, amines and carbonyl-containing compounds. The sensor arrays were initially deployed in different rooms in a single household having different occupant activity types and levels. Sensor responses were shown to differ for different room settings on the basis of occupancy levels and the nature of the room emission sources. Sensor responses relating to specific activities such as cooking, cleaning, office work, etc were noted in the temporal response. Subsequently, the colorimetric sensor arrays were deployed in a broader study across 9 different households and, using multivariate analysis, the sensor responses were shown to correlate strongly with household occupant activity and year of house build. Overall, this study demonstrates the significant potential for this type of simple approach to indoor air pollution monitoring in residential environments.

Microbial exposures in moisture-damaged schools and associations with respiratory symptoms in students: A multi-country environmental exposure study.

Moisture-damaged buildings are associated with respiratory symptoms and underlying diseases among building occupants, but the causative agent(s) remain a mystery. We first identified specific fungal and bacterial taxa in classrooms with moisture damage in Finnish and Dutch primary schools. We then investigated associations of the identified moisture damage indicators with respiratory symptoms in more than 2700 students. Finally, we explored whether exposure to specific taxa within the indoor microbiota may explain the association between moisture damage and respiratory health. Schools were assessed for moisture damage through detailed inspections, and the microbial composition of settled dust in electrostatic dustfall collectors was determined using marker-gene analysis. In Finland, there were several positive associations between particular microbial indicators (diversity, richness, individual taxa) and a respiratory symptom score, while in the Netherlands, the associations tended to be mostly inverse and statistically non-significant. In Finland, abundance of the Sphingomonas bacterial genus and endotoxin levels partially explained the associations between moisture damage and symptom score. A few microbial taxa explained part of the associations with health, but overall, the observed associations between damage-associated individual taxa and respiratory health were limited.

Influence of wood species on toxicity of log-wood stove combustion aerosols: a parallel animal and air-liquid interface cell exposure study on spruce and pine smoke.

BACKGROUND: Wood combustion emissions have been studied previously either by in vitro or in vivo models using collected particles, yet most studies have neglected gaseous compounds. Furthermore, a more accurate and holistic view of the toxicity of aerosols can be gained with parallel in vitro and in vivo studies using direct exposure methods. Moreover, modern exposure techniques such as air-liquid interface (ALI) exposures enable better assessment of the toxicity of the applied aerosols than, for example, the previous state-of-the-art submerged cell exposure techniques. METHODS: We used three different ALI exposure systems in parallel to study the toxicological effects of spruce and pine combustion emissions in human alveolar epithelial (A549) and murine macrophage (RAW264.7) cell lines. A whole-body mouse inhalation system was also used to expose C57BL/6 J mice to aerosol emissions. Moreover, gaseous and particulate fractions were studied separately in one of the cell exposure systems. After exposure, the cells and animals were measured for various parameters of cytotoxicity, inflammation, genotoxicity, transcriptome and proteome. RESULTS: We found that diluted (1:15) exposure pine combustion emissions (PM1 mass 7.7 ± 6.5 mg m- 3, 41 mg MJ- 1) contained, on average, more PM and polycyclic aromatic hydrocarbons (PAHs) than spruce (PM1 mass 4.3 ± 5.1 mg m- 3, 26 mg MJ- 1) emissions, which instead showed a higher concentration of inorganic metals in the emission aerosol. Both A549 cells and mice exposed to these emissions showed low levels of inflammation but significantly increased genotoxicity. Gaseous emission compounds produced similar genotoxicity and a higher inflammatory response than the corresponding complete combustion emission in A549 cells. Systems biology approaches supported the findings, but we detected differing responses between in vivo and in vitro experiments. CONCLUSIONS: Comprehensive in vitro and in vivo exposure studies with emission characterization and systems biology approaches revealed further information on the effects of combustion aerosol toxicity than could be achieved with either method alone. Interestingly, in vitro and in vivo exposures showed the opposite order of the highest DNA damage. In vitro measurements also indicated that the gaseous fraction of emission aerosols may be more important in causing adverse toxicological effects. Combustion aerosols of different wood species result in mild but aerosol specific in vitro and in vivo effects.

Human airway construct model is suitable for studying transcriptome changes associated with indoor air particulate matter toxicity.

In vitro models mimicking the human respiratory system are essential when investigating the toxicological effects of inhaled indoor air particulate matter (PM). We present a pulmonary cell culture model for studying indoor air PM toxicity. We exposed normal human bronchial epithelial cells, grown on semi-permeable cell culture membranes, to four doses of indoor air PM in the air-liquid interface. We analyzed the chemokine interleukin-8 concentration from the cell culture medium, protein concentration from the apical wash, measured tissue electrical resistance, and imaged airway constructs using light and transmission electron microscopy. We sequenced RNA using a targeted RNA toxicology panel for 386 genes associated with toxicological responses. PM was collected from a non-complaint residential environment over 1 week. Sample collection was concomitant with monitoring size-segregated PM counts and determination of microbial levels and diversity. PM exposure was not acutely toxic for the cells, and we observed up-regulation of 34 genes and down-regulation of 17 genes when compared to blank sampler control exposure. The five most up-regulated genes were related to immunotoxicity. Despite indications of incomplete cell differentiation, this model enabled the comparison of a toxicological transcriptome associated with indoor air PM exposure.

Emissions from a fast-pyrolysis bio-oil fired boiler: Comparison of health-related characteristics of emissions from bio-oil, fossil oil and wood.

There is currently great interest in replacing fossil-oil with renewable fuels in energy production. Fast pyrolysis bio-oil (FPBO) made of lignocellulosic biomass is one such alternative to replace fossil oil, such as heavy fuel oil (HFO), in energy boilers. However, it is not known how this fuel change will alter the quantity and quality of emissions affecting human health. In this work, particulate emissions from a real-scale commercially operated FPBO boiler plant are characterized, including extensive physico-chemical and toxicological analyses. These are then compared to emission characteristics of heavy fuel-oil and wood fired boilers. Finally, the effects of the fuel choice on the emissions, their potential health effects and the requirements for flue gas cleaning in small-to medium-sized boiler units are discussed. The total suspended particulate matter and fine particulate matter (PM1) concentrations in FPBO boiler flue gases before filtration were higher than in HFO boilers and lower or on a level similar to wood-fired grate boilers. FPBO particles consisted mainly of ash species and contained less polycyclic aromatic hydrocarbons (PAH) and heavy metals than had previously been measured from HFO combustion. This feature was clearly reflected in the toxicological properties of FPBO particle emissions, which showed less acute toxicity effects on the cell line than HFO combustion particles. The electrostatic precipitator used in the boiler plant efficiently removed flue gas particles of all sizes. Only minor differences in the toxicological properties of particles upstream and downstream of the electrostatic precipitator were observed, when the same particulate mass from both situations was given to the cells.

Oxidative capacity and hemolytic activity of settled dust from moisture-damaged schools.

Exposure to moisture-damaged indoor environments is associated with adverse respiratory health effects, but responsible factors remain unidentified. In order to explore possible mechanisms behind these effects, the oxidative capacity and hemolytic activity of settled dust samples (n = 25) collected from moisture-damaged and non-damaged schools in Spain, the Netherlands, and Finland were evaluated and matched against the microbial content of the sample. Oxidative capacity was determined with plasmid scission assay and hemolytic activity by assessing the damage to isolated human red blood cells. The microbial content of the samples was measured with quantitative PCR assays for selected microbial groups and by analyzing the cell wall markers ergosterol, muramic acid, endotoxins, and glucans. The moisture observations in the schools were associated with some of the microbial components in the dust, and microbial determinants grouped together increased the oxidative capacity. Oxidative capacity was also affected by particle concentration and country of origin. Two out of 14 studied dust samples from moisture-damaged schools demonstrated some hemolytic activity. The results indicate that the microbial component connected with moisture damage is associated with increased oxidative stress and that hemolysis should be studied further as one possible mechanism contributing to the adverse health effects of moisture-damaged buildings.

Toxicity of airborne dust as an indicator of moisture problems in school buildings.

Moisture-damaged indoor environments are thought to increase the toxicity of indoor air particulate matter (PM), indicating that a toxicological assay could be used as a method for recognizing buildings with indoor air problems. We aimed to test if our approach of analyzing the toxicity of actively collected indoor air PM in vitro differentiates moisture-damaged from non-damaged school buildings. We collected active air samples with NIOSH Bioaerosol Cyclone Samplers from moisture-damaged (index) and non-damaged (reference) school buildings (4 + 4). The teachers and pupils of the schools were administered a symptom questionnaire. Five samples of two size fractions [Stage 1 (>1.9 µm) and Stage 2 (1-1.9 µm)] were collected from each school. Mouse RAW264.7 macrophages were exposed to the collected PM for 24 h and subsequently analyzed for changes in cell metabolic activity, production of nitric oxide (NO), tumor necrosis factor (TNF)-α and interleukin (IL)-6. The teachers working in the moisture-damaged schools reported respiratory symptoms such as cough (p = 0.01) and shortness of breath (p = 0.01) more often than teachers from reference schools. Toxicity of the PM sample as such did not differentiate index from reference building,s but the toxicity adjusted for the amount of the particles tended to be higher in moisture-damaged schools. Further development of the method will require identification of other confounding factors in addition to the necessity to adjust for differences in particle counts between samples.

Evaluation of sampling methods for toxicological testing of indoor air particulate matter.

There is a need for toxicity tests capable of recognizing indoor environments with compromised air quality, especially in the context of moisture damage. One of the key issues is sampling, which should both provide meaningful material for analyses and fulfill requirements imposed by practitioners using toxicity tests for health risk assessment. We aimed to evaluate different existing methods of sampling indoor particulate matter (PM) to develop a suitable sampling strategy for a toxicological assay. During three sampling campaigns in moisture-damaged and non-damaged school buildings, we evaluated one passive and three active sampling methods: the Settled Dust Box (SDB), the Button Aerosol Sampler, the Harvard Impactor and the National Institute for Occupational Safety and Health (NIOSH) Bioaerosol Cyclone Sampler. Mouse RAW264.7 macrophages were exposed to particle suspensions and cell metabolic activity (CMA), production of nitric oxide (NO) and tumor necrosis factor (TNFα) were determined after 24 h of exposure. The repeatability of the toxicological analyses was very good for all tested sampler types. Variability within the schools was found to be high especially between different classrooms in the moisture-damaged school. Passively collected settled dust and PM collected actively with the NIOSH Sampler (Stage 1) caused a clear response in exposed cells. The results suggested the higher relative immunotoxicological activity of dust from the moisture-damaged school. The NIOSH Sampler is a promising candidate for the collection of size-fractionated PM to be used in toxicity testing. The applicability of such sampling strategy in grading moisture damage severity in buildings needs to be developed further in a larger cohort of buildings.

Chemical and microbial components of urban air PM cause seasonal variation of toxicological activity.

The chemical and microbial composition of urban air particulate matter (PM) displays seasonal variation that may affect its harmfulness on human health. We studied the in vitro inflammatory and cellular metabolic activity/cytotoxicity of urban air particulate samples collected in four size-ranges (PM10-2.5, PM2.5-1, PM1-0.2, PM0.2) during four seasons in relatively clean urban environment in Helsinki, Finland. The composition of the same samples were analyzed, including ions, elements, PAH compounds and endotoxins. In addition, microbial contribution on the detected responses was studied by inhibiting the endotoxin-induced responses with Polymyxin B both in the PM samples and by two different bacterial strains representing Gram-positive and -negative bacteria. Macrophage cell line (RAW 264.7) was exposed to the size segregated particulate samples as well as to microbe samples for 24h and markers of inflammation and cytotoxicity were analyzed. The toxicological responses were dependent on the dose as well as size range of the particles, PM10-2.5 being the most potent and smaller size ranges having significantly smaller responses. Samples collected during spring and autumn had in most cases the highest inflammatory activity. Soil components and other non-exhaust particulate emissions from road traffic correlated with inflammatory responses in coarse particles. Instead, PAH-compounds and K(+) had negative associations with the particle-induced inflammatory responses in fine particles, suggesting the role of incomplete biomass combustion. Endotoxin content was the highest in PM10-2.5 samples and correspondingly, the largest decrease in the responses by Polymyxin B was seen with the very same samples. We found also that inhibitory effect of Polymyxin B was not completely specific for Gram-negative bacteria. Thus, in addition to endotoxin, also other microbial components may have a significant effect on the toxicological responses by ambient particulate matter.

Source-specific fine particulate air pollution and systemic inflammation in ischaemic heart disease patients.

OBJECTIVE: To compare short-term effects of fine particles (PM2.5; aerodynamic diameter <2.5 µm) from different sources on the blood levels of markers of systemic inflammation. METHODS: We followed a panel of 52 ischaemic heart disease patients from 15 November 2005 to 21 April 2006 with clinic visits in every second week in the city of Kotka, Finland, and determined nine inflammatory markers from blood samples. In addition, we monitored outdoor air pollution at a fixed site during the study period and conducted a source apportionment of PM2.5 using the Environmental Protection Agency's model EPA PMF 3.0. We then analysed associations between levels of source-specific PM2.5 and markers of systemic inflammation using linear mixed models. RESULTS: We identified five source categories: regional and long-range transport (LRT), traffic, biomass combustion, sea salt, and pulp industry. We found most evidence for the relation of air pollution and inflammation in LRT, traffic and biomass combustion; the most relevant inflammation markers were C-reactive protein, interleukin-12 and myeloperoxidase. Sea salt was not positively associated with any of the inflammatory markers. CONCLUSIONS: Results suggest that PM2.5 from several sources, such as biomass combustion and traffic, are promoters of systemic inflammation, a risk factor for cardiovascular diseases.

The effect of assay type and sample matrix on detected cytokine concentrations in human blood serum and nasal lavage fluid.

Cytokine concentrations in biological fluids are widely used markers for activation of immunological processes. Confirming the reproducibility of measurements is important, especially in longitudinal or multicenter studies where time between analyses or different analyzing laboratories increases the intra-assay variability. In this study, the reproducibility of the cytokine analysis conducted with different assay platforms was studied by comparing the results of two cytokines [interleukin (IL)-6 in serum and nasal lavage fluid (NAL) and IL-8 in NAL] analyzed with Meso Scale Discovery (MSD) ultra-sensitive single and multiplex assay kits (n=76). In addition, the difference in cytokine levels between two biological sample matrices was studied by comparing the results of altogether 9 cytokines [IL-6, IL-2, IL-8, IL12p70, IL-1ß, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon (IFN)γ, IL-10 and tumor necrosis factor (TNF)α] measured from serum and NAL of the same study subjects (n=460). The results show that the cytokine concentrations analyzed with single and multiplex assays are concordant but not equal. Comparison of the different matrices revealed that cytokine concentrations in serum do not correspond with concentrations detected in nasal lavage fluid. It can be concluded that comparability of the results from single and multiplex analysis of cytokines is high, but the concentrations should not be compared directly with each other. The differences between concentrations analyzed from serum and nasal lavage fluid indicate that the levels are specific for each matrix and represent distinct immunological conditions.

Dampness and mould in schools and respiratory symptoms in children: the HITEA study.

BACKGROUND: The adverse respiratory health effects of dampness and mould in the home have been extensively reported, but few studies have evaluated the health effects of such exposures in schools. OBJECTIVES: To assess the associations between dampness and mould in school buildings and respiratory symptoms among 6-12-year-old pupils in three European countries with different climates. METHODS: Based on information from self-reports and observations, we selected 29 primary schools with and 27 without moisture damage in Spain, the Netherlands and Finland. Information on respiratory symptoms and potential determinants was obtained using a parent-administered questionnaire among 6-12-year-old pupils. Country-specific associations between moisture damage and respiratory symptoms were evaluated using multivariable multilevel mixed effects logistic regression analysis. RESULTS: Data from 9271 children were obtained. Nocturnal dry cough was consistently associated with moisture damage at school in each of the three countries: OR 1.15; 95% CI 1.00 to 1.30 with p for heterogeneity 0.54. Finnish children attending a moisture damaged school more often had wheeze (OR 1.36; CI 1.04 to 1.78), nasal symptoms (OR 1.34; CI 1.05 to 1.71) and respiratory-related school absence (OR 1.50; CI 1.10 to 2.03). No associations with these symptoms were found in the Netherlands or Spain (p for heterogeneity <0.05). CONCLUSIONS: Moisture damage in schools may have adverse respiratory health effects in pupils. Finnish school children seem to be at higher risk, possibly due to quantitative and/or qualitative differences in exposure.

Low-level exposure to ambient particulate matter is associated with systemic inflammation in ischemic heart disease patients.

Short-term exposure to ambient air pollution is associated with increased cardiovascular mortality and morbidity. This adverse health effect is suggested to be mediated by inflammatory processes. The purpose of this study was to determine if low levels of particulate matter, typical for smaller cities, are associated with acute systemic inflammation. Fifty-two elderly individuals with ischemic heart disease were followed for six months with biweekly clinical visits in the city of Kotka, Finland. Blood samples were collected for the determination of inflammatory markers interleukin (IL)-1ß, IL-6, IL-8, IL-12, interferon (IFN)γ, C-reactive protein (CRP), fibrinogen, myeloperoxidase and white blood cell count. Particle number concentration and fine particle (particles with aerodynamic diameters <2.5 µm (PM(2.5))) as well as thoracic particle (particles with aerodynamic diameters <10 µm (PM(10))) mass concentration were measured daily at a fixed outdoor measurement site. Light-absorbance of PM(2.5) filter samples, an indicator of combustion derived particles, was measured with a smoke-stain reflectometer. In addition, personal exposure to PM(2.5) was measured with portable photometers. During the study period, wildfires in Eastern Europe led to a 12-day air pollution episode, which was excluded from the main analyses. Average ambient PM(2.5) concentration was 8.7 µg/m(3). Of the studied pollutants, PM(2.5) and absorbance were most strongly associated with increased levels of inflammatory markers; most notably with C-reactive protein and IL-12 within a few days of exposure. There was also some evidence of an effect of particulate air pollution on fibrinogen and myeloperoxidase. The concentration of IL-12 was considerably (227%) higher during than before the forest fire episode. These findings show that even low levels of particulate air pollution from urban sources are associated with acute systemic inflammation. Also particles from wildfires may exhibit pro-inflammatory effects.

Serum myeloperoxidase is independent of the risk factors of atherosclerosis.

OBJECTIVES: The main hypothesis of the study was that as serum myeloperoxidase (MPO) concentration is known to indicate the progression of the atherosclerotic process, MPO may be associated with common risk factors of atherosclerosis. Therefore, the presence of these risk factors (especially elevated glucose and lipid concentrations) should predict an increased MPO level during the subsequent months. We also hypothesized an association of MPO with markers of other chronic diseases involving inflammation. METHODS: Fifty-three patients with ischemic heart disease were followed for 24 weeks by biweekly visits, during which the basic MPO level was measured (500 measurements in total, 2-12 per patient). The association of the patients' typical MPO with the risk factors of atherosclerosis and other personal determinants was examined by trend analysis and analysis of variance. RESULTS: MPO was statistically significantly associated with blood leukocyte, neutrophil, and lymphocyte concentrations of the patients (P=0.001-0.003). MPO was also associated with high-sensitivity C-reactive protein (P=0.02). MPO was not associated with markers of lipid and glucose metabolism, of atherosclerosis, or of other chronic diseases. CONCLUSION: Contradictory to our hypotheses, the results indicate that the serum MPO level is independent of the commonly measured risk factors of atherosclerosis and markers of other chronic diseases. Consequently, the findings suggest that MPO-related acute pathologic events (such as plaque destabilization) are not associated with the preceding glucose or lipid values. However, the results support the third hypothesis and previously reported view that MPO is a marker of inflammation in patients of ischemic heart disease.

Exhaled nitric oxide and atherosclerosis.

BACKGROUND: Fractional exhaled nitric oxide concentration (FENO) measurement has been proposed to be an important adjunct in the diagnosis and management of asthma, pulmonary hypertension and cystic fibrosis. But do we understand how other diseases influence the FENO values? In particular, atherosclerosis is one of the pathological conditions, in which nitric oxide (NO) production is inhibited and its degradation enhanced. Therefore, hypothesis of the current study was that FENO is inversely associated with risk markers of atherosclerosis and with diseases leading secondarily to the progression of atherosclerosis. MATERIALS AND METHODS: A long-term FENO value (median of biweekly measurements over a 24-week period) of 53 patients with ischaemic heart disease (IHD) was compared with the results of clinical and biochemical analyses. RESULTS: Fractional exhaled NO was inversely associated with the plasma concentration of triglycerides (P = 0·01) and with the blood concentration of glycated haemoglobin A1c (P = 0·03). It also tended to be inversely associated with the plasma glucose concentration (P = 0·10). However, there were no statistically significant associations with inflammatory or other biochemical markers, health status, lifestyle or other personal determinants. CONCLUSIONS: In accordance with the hypothesis, FENO is inversely associated with some of risk markers of atherosclerosis in patients with stable IHD (triglycerides and haemoglobin A1c, a marker of hyperglycaemic metabolism). A potential explanation is that, at hyperglycaemia and with higher triglyceride concentrations, atherosclerosis leads to endothelial dysfunction and, subsequently, to decreased production and increased degradation of NO.

Immunotoxicological properties of airborne particles at landfill, urban and rural sites and their relation to microbial concentrations.

We investigated the immunotoxicological activity of airborne particles in three different environments during 11 months. Specifically, we analyzed the relation of the immunotoxicological activity to microbial concentrations. During the study period, samples from a landfill, an urban and a rural site were collected on filters once a month. The immunotoxicological characteristics of collected particle samples were studied by exposing mouse macrophages (RAW264.7), and measuring the viability and production of inflammatory mediators i.e. nitric oxide (NO), tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 after 24 hours. In addition, the results were compared to corresponding microbial concentrations measured with quantitative polymerase chain reaction (qPCR) in the same sites. The particles collected from the landfill caused significantly more toxicity and inflammatory responses than the particles from other sites. The immunotoxicological activity of the samples changed according to the season, being the lowest in all study sites in the winter. In the rural and urban sites the responses peaked during the spring, whereas at the landfill the highest responses were detected towards the fall. All immunotoxic responses correlated strongly with airborne microbial concentrations at the landfill, whereas on the other sites the correlations were weaker. These results indicate that the overall immunotoxicological activity of the particles is increased in waste handling area with a heavy microbial load. The activity of the samples collected from different sites changes according to the season being at their lowest at wintertime. At the waste center, the immunotoxicological responses are related with concentrations of microbes, whereas at rural area and city center other factors seem to govern the toxicity of the sample.

The effect of ozonization on furniture dust: microbial content and immunotoxicity in vitro.

Moisture and mold problems in buildings contaminate also the furniture and other movable property. If cleaning of the contaminated furniture is neglected, it may continue to cause problems to the occupants even after the moisture-damage repairs. The aim of this study was to determine the effectiveness of high-efficiency ozone treatment in cleaning of the furniture from moisture-damaged buildings. In addition, the effectiveness of two cleaning methods was compared. Samples were vacuumed from the padded areas before and after the treatment. The microbial flora and concentrations in the dust sample were determined by quantitative cultivation and QPCR-methods. The immunotoxic potential of the dust samples was analyzed by measuring effects on cell viability and production of inflammatory mediators in vitro. Concentrations of viable microbes decreased significantly in most of the samples after cleaning. Cleaning with combined steam wash and ozonisation was more effective method than ozonising alone, but the difference was not statistically significant. Detection of fungal species with PCR showed a slight but nonsignificant decrease in concentrations after the cleaning. The immunotoxic potential of the collected dust decreased significantly in most of the samples. However, in a small subgroup of samples, increased concentrations of microbes and immunotoxicological activity were detected. This study shows that a transportable cleaning unit with high-efficiency ozonising is in most cases effective in decreasing the concentrations of viable microbes and immunotoxicological activity of the furniture dust. However, the method does not destroy or remove all fungal material present in the dust, as detected with QPCR analysis, and in some cases the cleaning procedure may increase the microbial concentrations and immunotoxicity of the dust.

Maturation of cytokine-producing capacity from birth to 1 yr of age.

Little is known about the immunologic maturation in the early stages of life. The aim of this study was to investigate maturation of immune system from birth to 1 yr of age and to compare immune functions between mothers and their children. Also the effect of atopy to the immune responses of children was examined. Cord blood samples (n = 228) and peripheral blood samples of children (n = 200) and their mothers (n = 208) 1 yr after birth were collected. Whole blood samples were stimulated for 24 and 48 h with Staphylococcal enterotoxin B (SEB), lipopolysaccharide (LPS) and the combination of phorbol ester and ionomycin (P/I). Production of TNF-alpha, IFN-gamma, IL-5, IL-8 and IL-10 was determined using ELISA. Significant mother-to-child correlation was detected in cytokine-producing capacity at the age of 1 yr. TNF-alpha (P/I, SEB and LPS stimulation), IFN-gamma (P/I and SEB), IL-5 (P/I and SEB) and IL-10 (P/I, SEB and LPS) producing capacity increased from birth to 1 yr of age. In general, stimulated cytokine responses were higher in mothers' than in children's blood samples, except in the case of P/I and LPS-stimulated IL-8, which were highest at birth. Maternal inhalation atopy was associated with increased cord blood IL-5 (24 and 48 h) and IL-10 (48 h) production following P/I stimulation. Also children of food atopic mothers expressed elevated cord blood IL-10 (48 h, P/I) responses and decreased IFN-gamma/IL-5 ratio (24 h, P/I). In addition, the production of IFN-gamma (24 and 48 h, P/I) and the IFN-gamma/IL-5 ratio (24 h and 48 h, P/I) at the age of 1 yr was lower among children with food atopic mothers. In conclusion, our results suggest that both adaptive and innate immune responses increase from birth to 1 yr of age, but are still weak in comparison to adult responses. Cytokine responses of children begin to correlate with those of their mothers during the first year of life. Although only few associations were observed between atopy and cytokine-producing capacity, our results suggest that children of atopic mothers express T(h)2-polarized cytokine pattern.